/Engine/Plugins/Experimental/Mutable/Source/CustomizableObjectEditor/Classes/MuCOE/Nodes/CustomizableObjectNodeEditMaterial.h
Returns the Image mask pin of the given Image that will be edited.
Always returns a valid pin if EditsImage(const FGuid&) returns true.
const [UEdGraphPin](API\Runtime\Engine\EdGraph\UEdGraphPin) * GetUsedImageMaskPin ( const [FGuid](API\Runtime\Core\Misc\FGuid) & ImageId ) const